EFFECT OF SILAID AND ETHREL ON PEACH LEAF AND FRUIT ABSCISSION IN RELATION TO THE KINETICS OF ETHYLENE RELEASE

The ethylene releasing compound (ERC) Silaid was evaluated as a fruit thinning agent in peach.
Silaid was applied 30 days post-bloom to trees.
Extent of fruit and leaf abscission were determined 12 d after spraying. 200 ppm Silaid resulted in commercially acceptable fruit abscission with minimal defoliation.
Another ERC, Ethrel, has been reported to cause excessive leaf abscission when compared to Silaid.
Different amounts of leaf abscission may be associated with differences in the kinetics of ethylene release during decomposition.
Leaf abscission is negatively correlated with the rate of ethylene release.
Equimolar amounts of Ethrel and Silaid, pH 7, 25 C, were applied to peach leaves and ethylene evolution measured as a function of time.
The rate constant (k) for ethylene generation from Ethrel and Silaid treated leaves was 1.15 and 1.49 x 10–2 hr-1, indicating a 22.8% higher rate of ethylene generation from Silaid than Ethrel.
The data supports the hypothesis that leaf abscission may require a longer exposure to ethylene than fruit abscission.

Manipulation of Ethylene Responses in Horticulture, XXII IHC

S.C. Perry, T.J. Gianfagna

https://doi.org/10.17660/ActaHortic.1987.201.16